Foram encontradas 395 questões.
Sobre o processo de abertura comercial e financeira da década de 1990, é correto afirmar:
Item 1 - os investimentos diretos externos na segunda metade da década de 1990 foram destinados menos ao setor industrial do que ao setor de serviços.
Provas
Questão presente nas seguintes provas
Suponha que queremos estimar como a renda de um indivíduo varia ao longo do ciclo de vida. Queremos testar a teoria de que a renda do indivíduo cresce a partir do momento que ele entra no mercado de trabalho até uma idade média, e depois começa a decrescer até o final do ciclo de vida. Usando dados de uma pesquisa anual para 14.368 trabalhadores, estimamos o seguinte modelo:
!$ Y_i=\beta_0+\beta_1X_{1i}+\beta_2X_{2i}+\beta_3X_{3i}+\beta4X_{1i}\,^2+ε_i !$,
em que !$ Y_i !$ é o logaritmo da renda mensal do indivíduo i, !$ X_{1i} !$ é a idade do indivíduo i, !$ X_{2i} !$ é uma variável binária que é igual 1 se o indivíduo é homem e !$ X_{3i} !$ representa o número de anos de estudo do indivíduo i.
Estimando o modelo por Mínimos Quadrados Ordinários, obtemos o seguinte resultado, em que os valores em parênteses abaixo dos coeficientes representam os erros-padrão: [Para a resolução desta questão talvez lhe seja útil saber que se Z tem distribuição normal padrão, então P(|Z|>1,645)=0,10 e P(|Z|>1,96)=0,05]

Item 0 - Se a teoria descrita acima é verdadeira, esperamos que o sinal de !$ \beta_1 !$ seja positivo e o sinal de !$ \beta_4 !$ negativo;
Provas
Questão presente nas seguintes provas
Julgue o item abaixo:
Item 0 - Suponha que X seja uma variável aleatória distribuída de acordo com a função densidade: f(x)=(1/2)x, em que 0≤x≤2. A probabilidade de que x se situe entre 0 e 1 é igual a 0,5;
Provas
Questão presente nas seguintes provas
Based on your interpretation of the following texts, determine whether each statement is right or wrong.
Text 1
(from The Economist print edition, March 30th – April 5th 2013)
Excerpts from:
Climate science
A sensitive matter
The climate may be heating up less in response to greenhouse-gas emissions than was once thought. But that does not mean the problem is going away
OVER the past 15 years air temperatures at the Earth’s surface have been flat while greenhouse-gas emissions have continued to soar. The world added roughly 100 billion tonnes of carbon to the atmosphere between 2000 and 2010. That is about a quarter of all the CO₂ put there by humanity since 1750. And yet, as James Hansen, the head of NASA’s Goddard Institute for Space Studies, observes, “the five-year mean global temperature has been flat for a decade.”
Temperatures fluctuate over short periods, but this lack of new warming is a surprise. Ed Hawkins, of the University of Reading, in Britain, points out that surface temperatures since 2005 are already at the low end of the range of projections derived from 20 climate models (…). If they remain flat, they will fall outside the models’ range within a few years.
The mismatch between rising greenhouse-gas emissions and not-rising temperatures is among the biggest puzzles in climate science just now. It does not mean global warming is a delusion. Flat though they are, temperatures in the first decade of the 21st century remain almost 1°C above their level in the first decade of the 20th. But the puzzle does
need explaining. (…)
The insensitive planet
The term scientists use to describe the way the climate reacts to changes in carbon-dioxide levels is “climate sensitivity”. This is usually defined as how much hotter the Earth will get for each doubling of CO₂ concentrations. So-called equilibrium sensitivity, the commonest measure, refers to the temperature rise after allowing all feedback mechanisms to work (but without accounting for changes in vegetation and ice sheets).
Carbon dioxide itself absorbs infra-red at a consistent rate. For each doubling of CO₂ levels you get roughly 1°C of warming. A rise in concentrations from preindustrial levels of 280 parts per million (ppm) to 560ppm would thus warm the Earth by 1°C. If that were all there was to worry about, there would, as it were, be nothing to worry about. A 1°C rise could be shrugged off. But things are not that simple, for two reasons. One is that rising CO₂ levels directly influence phenomena such as the amount of water vapour (also a greenhouse gas) and clouds that amplify or diminish the temperature rise. This affects equilibrium sensitivity directly, meaning doubling carbon concentrations would produce more than a 1°C rise in temperature. The second is that other things, such as adding soot and other aerosols to the atmosphere, add to or subtract from the effect of CO₂. All serious climate scientists agree on these two lines of reasoning. But they disagree on the size of the change that is predicted.
(...)
We can infer from the text that:
Item 1 - Climate does not react to changes in the carbon-dioxide levels;
Provas
Questão presente nas seguintes provas
Based on your interpretation of the following texts, determine whether each statement is right or wrong.
Text 1
(from The Economist print edition, March 30th – April 5th 2013)
Excerpts from:
Climate science
A sensitive matter
The climate may be heating up less in response to greenhouse-gas emissions than was once thought. But that does not mean the problem is going away
OVER the past 15 years air temperatures at the Earth’s surface have been flat while greenhouse-gas emissions have continued to soar. The world added roughly 100 billion tonnes of carbon to the atmosphere between 2000 and 2010. That is about a quarter of all the CO₂ put there by humanity since 1750. And yet, as James Hansen, the head of NASA’s Goddard Institute for Space Studies, observes, “the five-year mean global temperature has been flat for a decade.”
Temperatures fluctuate over short periods, but this lack of new warming is a surprise. Ed Hawkins, of the University of Reading, in Britain, points out that surface temperatures since 2005 are already at the low end of the range of projections derived from 20 climate models (…). If they remain flat, they will fall outside the models’ range within a few years.
The mismatch between rising greenhouse-gas emissions and not-rising temperatures is among the biggest puzzles in climate science just now. It does not mean global warming is a delusion. Flat though they are, temperatures in the first decade of the 21st century remain almost 1°C above their level in the first decade of the 20th. But the puzzle does
need explaining. (…)
The insensitive planet
The term scientists use to describe the way the climate reacts to changes in carbon-dioxide levels is “climate sensitivity”. This is usually defined as how much hotter the Earth will get for each doubling of CO₂ concentrations. So-called equilibrium sensitivity, the commonest measure, refers to the temperature rise after allowing all feedback mechanisms to work (but without accounting for changes in vegetation and ice sheets).
Carbon dioxide itself absorbs infra-red at a consistent rate. For each doubling of CO₂ levels you get roughly 1°C of warming. A rise in concentrations from preindustrial levels of 280 parts per million (ppm) to 560ppm would thus warm the Earth by 1°C. If that were all there was to worry about, there would, as it were, be nothing to worry about. A 1°C rise could be shrugged off. But things are not that simple, for two reasons. One is that rising CO₂ levels directly influence phenomena such as the amount of water vapour (also a greenhouse gas) and clouds that amplify or diminish the temperature rise. This affects equilibrium sensitivity directly, meaning doubling carbon concentrations would produce more than a 1°C rise in temperature. The second is that other things, such as adding soot and other aerosols to the atmosphere, add to or subtract from the effect of CO₂. All serious climate scientists agree on these two lines of reasoning. But they disagree on the size of the change that is predicted.
(...)
According to the text:
Item 0 - The lack of new warming is not surprising;
Provas
Questão presente nas seguintes provas
Com relação à análise do equilíbrio geral e eficiência econômica, indique se o item a seguir é certo ou errado:
Item 0 - Poder de mercado não é uma razão para falhas em mercados competitivos;
Provas
Questão presente nas seguintes provas
A respeito das funções utilidades e seus vários formatos, podemos afirmar:
Item 1 - Um consumidor que assume uma função utilidade na forma !$ U(x,y)=(x-x_0)^{\alpha}.(y-y_0)^{\beta} !$; !$ \alpha+\beta=1 !$ sempre vai adquirir no mínimo a quantidade !$ (x_0,y_0) !$ dos dois bens;
Provas
Questão presente nas seguintes provas
Julgue o item:
Item 4 - Sejam !$ f:R^2 \rightarrow R\ !$ e !$ g:R^2 \rightarrow R\ !$ definidas por !$ f(x,y)=4x+6y !$ e !$ g(x,y)=x^2+y^2 !$. Existem 2 pontos de máximo relativo de !$ f !$ sujeita à restrição !$ g(x,y)=13 !$.
Provas
Questão presente nas seguintes provas
Com relação a externalidades é possível afirmar:
Item 4 - Do ponto de vista social a produção de externalidades negativas deveria ter preço positivo.
Provas
Questão presente nas seguintes provas
A política econômica executada pelo Governo Dutra implicou consequências importantes para a economia brasileira. Sobre a política econômica desse período pode-se afirmar:
Item 1 - o diagnóstico oficial era que a inflação se devia ao excesso de demanda agregada.
Provas
Questão presente nas seguintes provas
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